vigenere

#include <cs50.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <stdlib.h>


int main(int argc, string argv[])

{
    if (argc != 2) //if user doesn't run command-line argument of one or enter positive int
    {
        printf("Usage: ./vigenere key\n"); //prompt them to run it again
        return 1; //returning zero means everything went well
    }

    for (int j = 0, n = strlen(argv[j]);  j < n; j++)  //length of the entire string. Save n as strlen for use in loop

        if (argc == 2 && isalpha(argv[j])) //if user doesn't run command-line argument of one or enter positive int and user inputs an alpha key, continue

        {
            printf("ciphertext: "); //Print after collecting plaintext
        }

}